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91.
Ashik Ahmed Md. Mehedi Hassan Galib Shafi Md. Kawsar Zaman Golam Sarowar 《Journal of The Franklin Institute》2018,355(1):197-217
In wind power system, low frequency oscillations are observed due to imbalance between mechanical input and electrical output. Hence, variable susceptance controllers are being adopted to mitigate these oscillations. However, improper modulation of control parameters also leads to system instability. Therefore, we propose an optimization methodology for mitigating low frequency oscillations in wind power generation system. To visualize our methodology, we use a lead-lag type variable susceptance controller for fixed speed induction generator (FSIG) based wind generation system. Then, we optimize gain and time constants of lead-lag controller using three optimization algorithms: particle swarm optimization (PSO), genetic algorithm (GA), and flower pollination algorithm (FPA). Later, we perform non-linear time domain simulation and quantitative analysis to find average fitness, standard deviation, run time, and iteration number for these optimization algorithms. Moreover, non-parametric statistical analysis, such as Kolmogorov–Smirnov and Wilcoxon signed-rank tests are employed for identifying statistically significant differences among these algorithms. 相似文献
92.
Abdul Samad Aziz Madhav Govind Kalekar Adinath Narayan Suryakar Tabita Benjamin Milsee Jaya Prakashan Bijle Mohammed Nadeem Ahmed Mehmood Sayyad 《Indian journal of clinical biochemistry : IJCB》2013,28(4):374-380
The present study aims to assess and compare the biochemical oxidative stress markers in male smokers and non-smokers with chronic periodontitis. One hundred thirty-four male chronic periodontitis patients and 64 apparently healthy male volunteers were recruited for the study. The periodontal status was evaluated by measuring gingival index, plaque index, papillary bleeding index and clinical attachment loss using UNC-15 probe. The biochemical markers estimated were total antioxidant capacity, RBC-superoxide dismutase, glutathione peroxidase, vitamin C, malondialdehyde and C-reactive protein. The obtained results indicate higher oxidative stress in chronic periodontitis. Smokers with chronic periodontitis show significantly higher periodontal clinical parameters and relatively higher systemic oxidative stress. Vitamin C estimation may be an important biochemical parameter in conjunction with clinical parameters for diagnosis of chronic periodontitis in smokers. 相似文献
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The present study carries out an impact analysis of a conditional cash transfer (CCT) program for secondary-school girls in seven districts of Khyber Pakhtunkhwa province in Pakistan, including Battagram, Bonair, Hangu, Kohistan, Shangla, Tank, and Upper Dir. In 2012 we collected household-level primary data and used a probit model for quantitative analysis. Further, we conducted various focus group discussions and key informant interviews in the target areas. Results show that the chances of female schooling decrease with a rise in family size. The chances of female education increase by 1.8 and by 3.3 % if household heads and their spouses have one additional year of schooling, respectively. Better educational services and rises in family income increase the chances of female ecucation by 11 and 0.3 %, respectively. Finally, socioeconomic awareness, improved economic conditions, and CCTs increase the chances of female education by 5.2, 4.7, and 0.03 %, respectively. Overall, the stipend program (CCTs) shows a pareto improvement. Our results indicate that 35 % of girls will drop out in the absence of a stipend program. The present study recommends that to increase program effectiveness, local-level monitoring and program evaluation may be improved, delays in stipend payments to female students should be reduced, a grievance redressal mechanism for parents and guardians should be introduced, and clear synergies should be developed with other transfer programs. 相似文献
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Ahmed Yaqinuddin Muhammad Zafar Muhammad Faisal Ikram Paul Ganguly 《Anatomical sciences education》2013,6(2):125-133
Assessing teaching‐learning outcomes in anatomical knowledge is a complex task that requires the evaluation of multiple domains: theoretical, practical, and clinical knowledge. In general, theoretical knowledge is tested by a written examination system constituted by multiple choice questions (MCQs) and/or short answer questions (SAQ). The assessment of practical knowledge (three‐dimensional anatomical concepts) involves oral, spot, or objective structured practical examinations (OSPE). Finally, the application of anatomical knowledge to patients is tested mainly through objective structured clinical examinations (OSCE). The major focus of this study is the OSPE. Although many schools challenge students using this tool in practical examinations in the early phase of the curriculum, the true meaning of OSPE is frequently forgotten and it becomes, in reality, a spot examination. This article, for the first time, describes how the concept of the OSPE has evolved and is currently being used to assess the practical domain of anatomical knowledge in a problem‐based curriculum at Alfaisal University College of Medicine. In addition, it describes the main differences from the spot examination, which is normally used in traditional medical curricula. The authors believe that the OSPE remains the most efficient tool to assess the practical aspects of anatomical knowledge in a system where basic knowledge is integrated with the clinical or functional part of anatomy. However, this contention only holds true if the OSPE process revolves around structured objectives. Anat Sci Educ 6: 125–133. © 2012 American Association of Anatomists. 相似文献
97.
Nowadays, companies and organizations are facing a deep economic crisis as a follow-up of the financial crisis that started in 2007. This crisis has affected a great amount of markets and industries around the world. In this context, companies are challenging the way they allocate resources to investments, especially to intangibles. The present research considers this issue based on an empirical work carried out with a large company (called here Global A) and with reference to the cycle approach proposed by Åkerman. General conclusions are derived for how to approach intangibles (intellectual capital) in a downturn context. 相似文献
98.
Ahmed Hassanien 《Higher Education in Europe》2007,32(2-3):135-150
The importance of group learning has increased significantly in higher education in the past two decades (Houldsworth and Mathews, 2000). The primary focus of this study is to explore the feelings and experience of students regarding group work and group assessment in higher education. The study is exploratory based on a qualitative focus group approach. Interestingly, students felt that group work is a significant method to foster the development of critical thinking through discussion, clarification of ideas, and evaluation of others' ideas. Students consider “poor communication” and “poor attendance at group meetings” as the main challenges they face when working within a group. Also, students identified “dedicated assignment seminars” as the most effective tool, which could be used to enhance the effectiveness of group work. This study reinforces the findings of previous research into group work suggesting that the experience is a generally positive one for students. Results are discussed in the context of current theoretical and empirical work on group‐based learning, education implications and areas for further research are discussed. 相似文献
99.
The relation between emotional and social development and family structure in the Sudanese capital, Khartoum, was examined. Children between the ages of 4 and 9 living in extended and nuclear families were compared on mothers' ratings of a range of childhood problems. Analysis revealed that children in nuclear families had more conduct, emotional, and sleep problems, poorer self-care, and were more likely to be overdependent than those living in extended families. They were also less likely to be breast fed, to be weaned later, and to have grandmothers involved in child care. Linear multiple regression revealed that, of these 3 childcare factors, grandmother's involvement was the strongest predictor of normal social and emotional adjustment. The possible protective characteristics of the extended family are discussed in relation to the importance of the grandmother as maternal advisor, social support, and socialization agent. 相似文献
100.